The deployment of spacecraft structures is a key part of rendering spacecraft operable for their intended purpose. The successful launching to a low orbit, separation, energization of the on-board thrusters for insertion into the proper orbit, and stabilization in the proper orbit, are of no avail if the antenna payload or the solar panels fail to deploy properly. The deployment hinge arrangement must be lightweight, reliable, and resistant to deformation after deployment, and withstand the rigors of the vacuum, high-radiation environment.
There is a substantial amount of art relating to hinges for deploying spacecraft structures. One type of prior-art hinge consists of a simple hinge, with a viscous filling between the moving parts of the hinge to provide damping. Such hinges require high machining tolerances, and may for that reason be expensive to build. Also, such hinges do not lock in any manner, and the deployed structure may be moved to a partially (or fully) stowed position due to thruster plume impingement, inertial torques, or other forces. For this reason, many prior-art hinges include latches, which operate when full deployment has been achieved. The latches themselves add to the cost and weight of the hinges, and the greater parts count tends to reduce the reliability of the hinge-latch arrangement. When the structure to be deployed is large, a plurality of hinges and latches may be required, and the concatenated reliability may be less than what is desired.
Other prior-art hinges may be simple, and provide some locking, such as that described in U.S. Pat. No. 5,196,857, issued Mar. 23, 1993 in the name of Chiappetta et al., describes a hinged antenna structure in which each hinge is made from curved elastic plates, such as graphite-epoxy plates. The cost or fabrication techniques for such structures may not be desired. Improved deployment hinges are desired.